A study of prisoners and guards in a simulated prison - Haney, C., Banks, C. and Zimbardo, P. (1973)

Are you a slightly different person at school and at home? Do you act differently with one group of friends than with another group? We all play different 'roles' in different situations. But what if the role you are playing requires you to be cruel, or violent, or even murderous? Would you still follow the role?

The full article can be found here and a good summary of the main themes and evaluation issues is on the Holah website here.

Assignment 1

Design a short questionnaire to investigate whether people you know think that dispositional or situational factors are most important in prison violence.

Collect at least 20 responses, and analyse the results. Do people tend to give situational or dispositional explanations? Draw a bar chart or other suitable graph of what you find.

Be prepared to report your findings back to the class.

Assignment 2

Create a timeline of the events of the Stanford Prison experiment using http://www.timetoast.com. Include as much detail as you can, and illustrate your events with appropriate pictures. To help you get a feel for how the website works, here's a sample timeline for Zimbardo's life.

Can you include more detail than the ones below?

Assignment 3

Complete these jigsaw activites on Zimbardo's method and his ethics. Rearrange the pieces to make sensible PEE points and then write them out into full evaluative paragraphs.

Submit your work through the form on the home page.

Alternative Study - Zimbardo et al as a field experiment or naturalistic observation?

Haney, Banks and Zimbardo conducted a controlled observation in laboratory conditions (sometimes this is simply called a lab experiment for simplicity).

If it was a lab experiment, then what was the independent variable?

1. Can you think of how you might conduct this study using an alternative research method? For example, could you design a field experiment to test the same aims, or perhaps a naturalistic observation (an observational study which takes place in the field)?

Write a description of the study, including the who, what, where and how.

2. What would the advantages and disadvantages of such an experiment be, compared to the original?

Evaluate this new study in practical and ethical terms.

Big Issue - Reliability and Validity

Reliability and validity are two of the most important terms in science.It is crucial that you understand the terms and that you can use them to evaluate the studies we look at this year.

Reliability is the consistency of a measurement. A reliable car or a footballer player gives you a similar result each time they operate. A reliable result in an experiment is exactly the same! If you repeat the measurement, you will get a very similar result.

Reliability relies on the consistency of both the thing that is being measured (internal reliability) AND the measuring device (external reliability). If either one of those changes too much then the result will not be reliable.

How can we test reliability?Internal reliability can be tested using the split half method. This is where the test/questionnaire etc is split in two. The participant does both halves and these can then be compared to each other. If the results are similar from the two halves of the test then this suggests that the test has internal validity.

External reliability can be tested for test-retest reliability. This is where a test (e.g. an IQ test) is take once and then repeated at a later point (e.g. two weeks later). If the test is a reliable measurement then it should give similar results both times (because it is unlikely that our IQ would change much in this time). If an experiment involves observers or judges, then another way of checking reliability is to obtain inter-observer (or inter-rater) reliability. This involves having two or more judges score the test and then checking to see that the results from each judge are similar. If they are, then their judgements can be said to be reliable.

Validity is whether or not a test measures what it claims to measure. Standing on a broken set of scales will not be a valid test of your weight, nor will taking an IQ test in a language you've never spoken be a valid test of your intelligence. In both of these cases the test will not actually be measuring the thing it is supposed to be measuring. There are many different types of validity, but for AS Level you should only know the following:

Internal validity is to do with the method of the study. If the IV has caused any change in the DV, then the procedure is a valid one, but if there may have been confounding variables which affected the DV as well, then it will not have internal validity.

Ecological validity is to do with whether the results of the study can be generalised to the real world. If the research took place in a very realistic environment, and the task was a familiar one, then it will be high in ecological validity. Lab experiments are often low in ecological validity, as they can require participants to do unfamiliar tasks in unusual, controlled environments. This may lead them to produce behaviours that they would not do normally, making the test invalid as a measure of normal behaviour. Take this lesson and quiz to find out more

Face validity is for measuring devices and it is very simple. It simply means whether or not a measuring device looks like it would be a good measure of the DV!

Predictive validity is for measuring devices. It covers whether the measurement is good at predicting future performance. For example, if a test in school is also good at predicting how much people will earn in their future jobs, we would say that the test has good predictive validity.

Which of these types of reliability and validity is relevant to Zimbardo? Can you relate them to any other studies that you've covered? Can you relate them to any other aspects of your life?

Revision

1. Can you complete this quiz of the details of the study without any notes?

2. Listen to this podcast from the BBC 'Mind Changers' series, and make notes of the key details of the study.

Extension

What's the point of prisons?

Poetic Justice Build prisons. Not day-care. Lock ’em up. What do we care? Hire cops, not counsellors. Staff courts, not clinics. Wage warfare, not welfare Invest in felons. Ripen ’em like melons. Eat ’em raw, then ask for more More poverty. More crime More men in prison. More fear in the street More ex-cons among us. Poetic justice Robert Johnson

Why do we send people to prison? Is it retribution (to 'pay them back')? To make everyone else safer or happier? To rehabilitate them so they will not cause problems in the future?

These issues are central to shaping prison policy, and which one you agree with will make a huge difference to the prison system you design. Read Haney and Zimbardo's thoughts on how they would like to see prisons change, written 25 years after the SPE.